iOS摄像头采集视频并硬编码
参考，代码转载自 简书：
https://www.jianshu.com/p/eccdcf43d7d2
https://www.jianshu.com/p/0d18f04e524d
还有GitHub上其他大佬的代码
#import <AVFoundation/AVFoundation.h> #import <VideoToolbox/VideoToolbox.h> @interface ViewController : UIViewController<AVCaptureVideoDataOutputSampleBufferDelegate> @property (strong, nonatomic) IBOutlet UIImageView *ShowCapView; @property (strong, nonatomic) IBOutlet UIButton *ShowButton;
// ViewController.m // // Created by yizhimao on 2020/3/31. // #import "ViewController.h" #import <CoreGraphics/CoreGraphics.h> #import <CoreVideo/CoreVideo.h> #import <CoreMedia/CoreMedia.h> typedef NS_ENUM(NSUInteger, VEVideoEncoderProfileLevel) { VEVideoEncoderProfileLevelBP, VEVideoEncoderProfileLevelMP, VEVideoEncoderProfileLevelHP }; @interface ViewController () //编码参数 @property (assign, nonatomic) VTCompressionSessionRef compressionSessionRef; @end @implementation ViewController{ AVCaptureSession *_captureSession; AVCaptureVideoPreviewLayer *_captureLayer; bool isCapturing; AVCaptureConnection* _VideoConnection ;//用于判断回调数据类型 AVCaptureConnection* _AudioConnection ; } - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. _captureSession = [[AVCaptureSession alloc] init];//首先初始化AVCaptureSessionz会话控制 // 不使用应用的实例，避免被异常挂断 _captureSession.usesApplicationAudioSession = NO; isCapturing = NO; self.ShowCapView.frame = CGRectMake(20, 20 , 200, 200); self.ShowButton.frame= CGRectMake(30, 230 , 60, 50); [self setCapSession]; [self ShowPic]; [self EncH264DataCreateFun]; } -(void)setCapSession{ // 配置采集输入源（摄像头） NSError *error = nil; // 获得一个采集设备，例如前置/后置摄像头 AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; // 用设备初始化一个采集的输入对象 AVCaptureDeviceInput *CapvideoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error]; if (error) { NSLog(@"Error getting video input device: %@", error.description); } //------- NSInteger framedur = 30;//设置帧间隔范围3-30毫秒 //activeFormat.videoSupportedFrameRateRanges to discover valid ranges AVFrameRateRange *frameRateRange = [CapvideoInput.device.activeFormat.videoSupportedFrameRateRanges objectAtIndex:0]; //NSLog(@"tramerate max %f min %f",frameRateRange .maxFrameRate ,frameRateRange.minFrameRate); if (framedur > frameRateRange.maxFrameRate || framedur < frameRateRange.minFrameRate) { //这里的比较是比较帧间隔，而不是帧率 return; } [videoDevice lockForConfiguration:NULL];//要锁上，否则会崩溃；用于获取设备配置使用权 //设置帧间隔，间隔最小对应最大的帧率 CapvideoInput.device.activeVideoMinFrameDuration = CMTimeMake(1, (int)framedur); CapvideoInput.device.activeVideoMaxFrameDuration = CMTimeMake(1, (int)framedur); [videoDevice unlockForConfiguration]; //-------- if ([_captureSession canAddInput:CapvideoInput]) { [_captureSession addInput:CapvideoInput]; // input 添加到Session } AVCaptureVideoDataOutput *captureOutput = [[AVCaptureVideoDataOutput alloc]init]; // 丢弃延迟的帧 captureOutput.alwaysDiscardsLateVideoFrames = YES; // 设置视频数据格式 NSDictionary *videoSetting = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange], kCVPixelBufferPixelFormatTypeKey, nil]; [captureOutput setVideoSettings:videoSetting]; dispatch_queue_t queue; queue = dispatch_queue_create("cameraQueue", NULL); // 为output添加 代理，在代理中就可以拿到采集到的原始视频数据 [captureOutput setSampleBufferDelegate:self queue:queue]; if ([_captureSession canAddOutput:captureOutput]) { [_captureSession addOutput:captureOutput]; // out put 添加到Session } // 保存Connection，用于在SampleBufferDelegate中判断数据来源（是Video/Audio？） _VideoConnection = [captureOutput connectionWithMediaType:AVMediaTypeVideo]; _AudioConnection = [captureOutput connectionWithMediaType:AVMediaTypeAudio]; // 设置分辨率 if ([_captureSession canSetSessionPreset:AVCaptureSessionPreset1280x720]) { _captureSession.sessionPreset = AVCaptureSessionPreset1280x720; } } -(void)ShowPic{ //实时显示摄像头内容这是AVCaptureSession的一个属性，集成自CALayer，通过类名我们可以知道这个layer是用来预览采集到的视频图像的，直接把这个layer加到UIView上面就可以实现采集到的视频实时预览了。 _captureLayer = [AVCaptureVideoPreviewLayer layerWithSession: _captureSession]; //设置预览时的视频缩放方式 _captureLayer.videoGravity = AVLayerVideoGravityResizeAspectFill; [[_captureLayer connection] setVideoOrientation:AVCaptureVideoOrientationPortrait]; // 设置视频的朝向竖屏 _captureLayer.frame = self.ShowCapView.layer.bounds; [self.ShowCapView.layer addSublayer: _captureLayer];//叠层 } - (IBAction)StartCapAndShow:(id)sender { [self startCapture]; } - (BOOL)startCapture { if (self->isCapturing) { [_captureSession stopRunning]; self->isCapturing = NO; return NO; } // 摄像头权限判断 AVAuthorizationStatus videoAuthStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo]; if (videoAuthStatus != AVAuthorizationStatusAuthorized) { return NO; } [_captureSession startRunning]; self->isCapturing = YES; return YES; } /** 输入待编码数据 @param sampleBuffer 待编码数据 @param forceKeyFrame 是否强制I帧 @return 结果 */ - (BOOL)videoEncodeInputData:(CMSampleBufferRef)sampleBuffer forceKeyFrame:(BOOL)forceKeyFrame { if (NULL == _compressionSessionRef) { return NO; } if (nil == sampleBuffer) { return NO; } CVImageBufferRef pixelBuffer = (CVImageBufferRef)CMSampleBufferGetImageBuffer(sampleBuffer); NSDictionary *frameProperties = @{(__bridge NSString *)kVTEncodeFrameOptionKey_ForceKeyFrame: @(forceKeyFrame)}; OSStatus status = VTCompressionSessionEncodeFrame(_compressionSessionRef, pixelBuffer, kCMTimeInvalid, kCMTimeInvalid, (__bridge CFDictionaryRef)frameProperties, NULL, NULL); if (noErr != status) { NSLog(@"VEVideoEncoder::VTCompressionSessionEncodeFrame failed! status:%d", (int)status); return NO; } return YES; } //启动后自己调用，底层输出的函数可能已经注册过了，直接在外边实现函数的使用即可。 - (void) captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection { // 这里的sampleBuffer就是采集到的数据了，但它是Video还是Audio的数据，得根据connection来判断 if (connection == _VideoConnection) { // Video // 取得当前视频尺寸信息 CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer); CVPixelBufferLockBaseAddress(pixelBuffer, 0); int width = CVPixelBufferGetWidth(pixelBuffer); int height = CVPixelBufferGetHeight(pixelBuffer); void *imageAddress = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);//yuv数据地址 ///write file // NSArray *dicts = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); // NSString *path = [dicts objectAtIndex:0]; // static FILE* fpdec; // if(fpdec == NULL) // { // fpdec = fopen([[NSString stringWithFormat:@"%@/yuv2.data", path] UTF8String], "wb");} // // fwrite(imageAddress, 1, (width *height * 3/2), fpdec); // fflush (fpdec); [self videoEncodeInputData:sampleBuffer forceKeyFrame:NO]; CVPixelBufferUnlockBaseAddress(pixelBuffer,0); //NSLog(@"在这里获得video sampleBuffer，做进一步处理（编码H.264）"); } else if (connection == _AudioConnection) { // Audio //NSLog(@"这里获得audio sampleBuffer，做进一步处理（编码AAC）"); //do nothing } } /* 1 ABR (Average Bit Rate) ----ios 在一定的时间范围内达到设定的码率，但是局部码率峰值可以超过设定的码率，平均码率恒定。可以作为VBR和CBR的一种折中选择。 2 设置H264编码的画质，H264有4种Profile：BP、EP、MP、HP 3 设置是否实时编码输出;配置是否产生B帧，High profile 支持 B 帧;配置I帧间隔 **/ -(void)EncH264DataCreateFun { //创建编码器 OSStatus status = VTCompressionSessionCreate(NULL, 1280, 720, kCMVideoCodecType_H264, NULL, NULL, NULL, encodeOutputDataCallback, (__bridge void *)(self), &_compressionSessionRef); // 设置码率 512kbps status = VTSessionSetProperty(_compressionSessionRef, kVTCompressionPropertyKey_AverageBitRate, (__bridge CFTypeRef)@(512 * 1024)); // 设置ProfileLevel为BP3.1 status = VTSessionSetProperty(_compressionSessionRef, kVTCompressionPropertyKey_ProfileLevel, kVTProfileLevel_H264_Baseline_3_1); // 设置实时编码输出（避免延迟） status = VTSessionSetProperty(_compressionSessionRef, kVTCompressionPropertyKey_RealTime, kCFBooleanTrue); // 配置是否产生B帧 status = VTSessionSetProperty(_compressionSessionRef, kVTCompressionPropertyKey_AllowFrameReordering, kCFBooleanFalse); status = VTSessionSetProperty(_compressionSessionRef, kVTCompressionPropertyKey_ExpectedFrameRate, (__bridge CFTypeRef)@(30)); // 配置最大I帧间隔 30帧 *2秒；也就是按照30帧率每秒，每两秒编一个GOP status = VTSessionSetProperty(_compressionSessionRef, kVTCompressionPropertyKey_MaxKeyFrameInterval, (__bridge CFTypeRef)@(30*2)); // 配置I帧持续时间 GOP持续时间2秒 status = VTSessionSetProperty(_compressionSessionRef, kVTCompressionPropertyKey_MaxKeyFrameIntervalDuration, (__bridge CFTypeRef)@(2.0)); // 编码器准备编码 status = VTCompressionSessionPrepareToEncodeFrames(_compressionSessionRef); } NSString *Pathtotal = nil; NSFileHandle * fileHandle = nil; //编码输出回调 void encodeOutputDataCallback(void * CM_NULLABLE outputCallbackRefCon, void * CM_NULLABLE sourceFrameRefCon, OSStatus status, VTEncodeInfoFlags infoFlags, CM_NULLABLE CMSampleBufferRef sampleBuffer) { if(Pathtotal == nil) { NSArray *dicts = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *path = [dicts objectAtIndex:0]; Pathtotal = [NSString stringWithFormat:@"%@/264.data", path] ; fileHandle = [NSFileHandle fileHandleForWritingAtPath:Pathtotal]; if(fileHandle == nil) { return; } [fileHandle seekToEndOfFile]; } if (noErr != status || nil == sampleBuffer) { NSLog(@"VEVideoEncoder::encodeOutputCallback Error : %d!", (int)status); return; } if (nil == outputCallbackRefCon) { return; } if (!CMSampleBufferDataIsReady(sampleBuffer)) { return; } if (infoFlags & kVTEncodeInfo_FrameDropped) { NSLog(@"VEVideoEncoder::H264 encode dropped frame."); return; } const char header[] = "\x00\x00\x00\x01"; size_t headerLen = (sizeof header) - 1; NSData *headerData = [NSData dataWithBytes:header length:headerLen]; // 判断是否是关键帧 bool isKeyFrame = !CFDictionaryContainsKey((CFDictionaryRef)CFArrayGetValueAtIndex(CMSampleBufferGetSampleAttachmentsArray(sampleBuffer, true), 0), (const void *)kCMSampleAttachmentKey_NotSync); if (isKeyFrame)//sps pps信息获取 { NSLog(@"VEVideoEncoder::编码了一个关键帧"); CMFormatDescriptionRef formatDescriptionRef = CMSampleBufferGetFormatDescription(sampleBuffer); // 关键帧需要加上SPS、PPS信息 size_t sParameterSetSize, sParameterSetCount; const uint8_t *sParameterSet; OSStatus spsStatus = CMVideoFormatDescriptionGetH264ParameterSetAtIndex(formatDescriptionRef, 0, &sParameterSet, &sParameterSetSize, &sParameterSetCount, 0); size_t pParameterSetSize, pParameterSetCount; const uint8_t *pParameterSet; OSStatus ppsStatus = CMVideoFormatDescriptionGetH264ParameterSetAtIndex(formatDescriptionRef, 1, &pParameterSet, &pParameterSetSize, &pParameterSetCount, 0); if (noErr == spsStatus && noErr == ppsStatus) { NSData *sps = [NSData dataWithBytes:sParameterSet length:sParameterSetSize]; NSData *pps = [NSData dataWithBytes:pParameterSet length:pParameterSetSize]; NSMutableData *spsData = [NSMutableData data]; [spsData appendData:headerData]; [spsData appendData:sps]; NSLog(@"write file key"); [fileHandle writeData:spsData]; NSMutableData *ppsData = [NSMutableData data]; [ppsData appendData:headerData]; [ppsData appendData:pps]; //[ppsData writeToFile:Pathtotal atomically:NO];//会覆盖 [fileHandle writeData:ppsData]; } } CMBlockBufferRef blockBuffer = CMSampleBufferGetDataBuffer(sampleBuffer); size_t length, totalLength; char *dataPointer; status = CMBlockBufferGetDataPointer(blockBuffer, 0, &length, &totalLength, &dataPointer); if (noErr != status) { NSLog(@"VEVideoEncoder::CMBlockBufferGetDataPointer Error : %d!", (int)status); return; } size_t bufferOffset = 0; static const int avcHeaderLength = 4; while (bufferOffset < totalLength - avcHeaderLength) { // 读取 NAL 单元长度 uint32_t nalUnitLength = 0; memcpy(&nalUnitLength, dataPointer + bufferOffset, avcHeaderLength); // 大端转小端 nalUnitLength = CFSwapInt32BigToHost(nalUnitLength); NSData *frameData = [[NSData alloc] initWithBytes:(dataPointer + bufferOffset + avcHeaderLength) length:nalUnitLength]; NSMutableData *outputFrameData = [NSMutableData data]; [outputFrameData appendData:headerData]; [outputFrameData appendData:frameData]; NSLog(@"write file frame %d",nalUnitLength); // [outputFrameData writeToFile:Pathtotal atomically:NO]; [fileHandle writeData:outputFrameData]; bufferOffset += avcHeaderLength + nalUnitLength; } } - (BOOL)stopVideoEncode { if (NULL == _compressionSessionRef) { return NO; } OSStatus status = VTCompressionSessionCompleteFrames(_compressionSessionRef, kCMTimeInvalid); if (noErr != status) { NSLog(@"VEVideoEncoder::VTCompressionSessionCompleteFrames failed! status:%d", (int)status); return NO; } return YES; } @end
注意记得添加摄像头权限 要不然会崩溃，以及高配运行黑屏问题。网上都有相应的解决办法。
浙公网安备 33010602011771号